Draft regulator



1941- w. B. STEPHENSON 2,268,343

DRAFT REGULATOR Filed Jan. 27, 1939 2 Sheets-Sheet l Dec. 30, 1941. w. B; STEPHENSON 2,268,348

DRAFT REGULATOR 2 Sheets-Sheet 2 WZZZzZzmBfifepke/zwn' M fi o/ Filed Jan. 27, 1939 Patented Dec. 30, 1941 UNITED STATES PATENT OFFICE DRAFT REGULATOR William B. Stephenson, Fond du Lac, Wis.

Application January 27, 1939, Serial No. 253,035

8 Claims.

The invention relates to draft regulators and has as its general aim the provision of a new and improved regulator arranged and adapted for use in substantially any flue installation.

The invention is especially applicable to automatic draft controllers for regulating the admission of atmospheric air into the flue gas outlet passage of a heating apparatus so as to maintain in normal operation a draft of a predetermined intensity in the fire box regardless of fluctuations in the conditions which tend to induce the draft. An automatic regulator of this character is commonly associated with a short stub pipe defining a branch air inlet passage to a part of the main flue gas outlet passage of the heating apparatus.

The arrangements of the flue pipes in heating apparatus installations may vary widely as determined by the location of the apparatus with reference to surrounding structures, and it may, therefore, be necessary to connect the stub pipe to a horizontal or to a vertical section of the flue pipe. Moreover, the location may require that the regulator swing upwardly or downwardly to provide proper clearance for outwardly extending parts of the regulator such as a counterbalance weight and its supporting structure.

An object of the invention is to provide a new and improved draft regulator which embodies means permitting the rearrangement of the movable parts of the regulator relative to the stub pipe toadapt the regulator for various installations.

Another object is to provide a new and improved draft regulator in which the swinging damper may be assembled to swing relative to the stub pipe in various directions and in which the counterbalancing weight assembly may be changed accordingly to operate properly in any selected relationship of the damper and frame.

Another object is to provide a novel breeching or flue pipe assembly adapted to be interposed in a fine pipe in either of two reversed positions and having associated therewith a damper structure and down draft diverter means, both of which are adjustable for operation in each of said positions.

A further object is to provide a novel diverter for directing down drafts toward the opening controlled by the draft regulator.

Other objects and advantages will become apparent in the following description and from the accompanying drawings, in which:

Fig. 1 is a perspective view of a flue pipe section and a connected draft regulator structure embodying the features of the invention.

Fig. 2 is a sectional view through the assembly on a horizontal plane indicated generally by the line 2-2 in Fig. 1.

Fig. 3 is a sectional view through the damper assembly along the line 3--3 in Fig. 2.

Figs. 4 and 5 are sectional views through the breeching taken respectively along the lines 4-4 and 5-5 in Fig. 2.

Fig. 6 is a view in side elevation showing a different relationship of the damper and its supporting structure.

While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit theinvention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

Referring more particularly to the drawings, a conduit which is generally representative of the flue pipe or breeching is designated at It and, in this instance, comprises a short pipe section arranged to be interposed in the flue pipe (not shown) by reduction connections H. At one side, and between its ends, the conduit has an enlarged aperture I2 (Fig. 21) affording communication with a stub pipe or duct I3 which is preferably square in cross section and is fashioned at one end to be snugly secured, as by rivets I4,

= to the conduit. The square open end of the duct receives a damper supporting frame I5 constructed to have a relatively tight sliding fit with the duct sothat its relative position may at will be conveniently changed. The frame may be suitably formed of pieces of angle iron spot-welded or otherwise rigidly joined at the corners of the frame and arranged with one leg I5 of the angle defining a square opening and with the other leg l5 extending outwardly for limiting abutment with the end of the duct.

A damper, in this instance, comprises a peripherally flanged flat plate l6 dimensioned to close the square opening defined by the frame leg I5 yet having sufficient clearance to permit it to be mounted for free swinging movement. Suitable means for detachably supporting the damper is shown in Fig. 3 as being a bowed member I! of resilient material, such as spring wire, anchored intermediate its ends, as at l8, to the plate. The

' ends of the member are outtumed, as at I 8, to

extend through alined holes 20 in the peripheral flange on the plate and into alined bearing apertures 2| formed in inwardly struck bosses 22 on the frame leg l. As shown in Fig. 3, the arrangement preferred locates the pivotal axis of the damper near one side edge thereof so that the damper may swing in either direction wholly to ward and away from one side of the duct.

Normally the duct should be closed or substantially so and counterbalancing means is provided for holding the damper in position to traverse the duct. This means is, according to the invention, arranged for adjustment to balance the damper operatively whenever it is positioned to respond to the force of gravity and regardless of the relationship of the duct to the flue pipeor of the pivotal axis of the damper to the duct. To this end, an, elongated arm 23 is secured at one end, as by bolts 24 or the like, to the damper adjacent to the pivotal axis thereof. The free portion of the arm is generally U-shaped and has a short end 23 extendin substantially perpendicularly outward from the exposed or front face of the damper, a base 23 extending beyond the side of the duct which parallels and is adjacent to the pivotal axis of the damper, and a long end 23 paralleling the short end 23 and extending across the plane of the damper. As best seen in Figs. 2 and 3, the end 23 is laterally offset from the end 23 to clear the duct in the swinging movement of the damper assembly. The arm end 23 is by this arrangement located on the opposite side of the pivotal axis from the main body of the damper and extends in a direction which is substantially perpendicular to the plane of the damper or normal to the damper axis.

The arm end carries adjustable weight means 25 comprising, in this instance, a sleeve 26 (Fig. 6) encircling the arm end 23 for slidable adjustment relative thereto and a set screw 21 manipulable by an enlarged massive head 28 to clamp the sleeve to the arm. The relationship of the arm and weight to the damper is such that the damper may be sensitively balanced in any selected relation of the damper and duct to swing inwardly or outwardly of the duct in response to draft fluctuations in the stack.

For example, in Fig. 1 the frame is shown as being mounted on the duct in such manner that the damper pivot is horizontal and adjacent to the bottom side of the duct. Since gravity tends to swing the damper open, this condition is representative of a relationship which requires the greatest counterbalancing force. Accordingly, the sleeve 26 is positioned on the arm end '23 with the weight 28 located on the side of the arm remote from the damper pivot. The center of mass of the weight assembly is, therefore, disposed for adjustment along a line which is at the greatest distance from the damper pivot.

Fig. 6 illustrates a relationship between the damper and the duct which is representative of an adjustment requiring the least counterbalancing force. The frame in this arrangement has been turned through 180 to locate the pivotal axis of the damper adjacent to the top side of the duct. Gravity tends to hold the damper in closed position. To adjust the counterbalancing weight, the sleeve 26 is removed from the arm 23 and reversed to locate the weight 28 on the side of the arm adjacent to the pivot. The center of mass of the assembly is, therefore, adjustable along a line close to the pivot, thereby substantially lessening the effectiveness of the weight assembly relative to the damper. 1

It may be said, therefore, that the arm end 23 extends in a plane which is intermediate or approximately midway between the two extreme positions of the center of mass of the counterbalancing weight required by the various relationships of the damper and duct. Intermediate adjustments of the weight assembly for other positions of the damper are effected by disposing the weight 28 on the proper sideof the arm end 23 and longitudinally adjusting it.

This arrangement permits the association of the duct with a flue pipe and of the damper structure with the duct in any desired manner and the single structure will meet any condition in which the damper is balanced against the force of gravity. Usually the duct will be properly connected with a horizontal or a vertical flue pipe and the damper frame shifted with respect to the duct so that the damper will swing upwardly or downwardly (Figs. 6 or 1, respectively) as desired. The proper balance is then effected by arranging the weight assembly accordingly. As an alternative to adjustment by shifting the frame, a plurality of pairs of bearing bosses 22 may be provided, as shown in Fig. 3 at 22', for selective engagement by the detachable damper supporting member IT.

A feature of the invention which operates in conjunction with the draft regulator is embodied in a down draft diverter or deflector, one form of which is shown in Figs. 2, 4 and 5. The short pipe or breeching section l8 has a diverter or deflector member 29 mounted therein for directing down or reverse drafts in the flue pipe toward the duct and swinging damper so that the force of such drafts is harmlessly expended through the damper controlled opening and cannot reach the fire box. Otherwise, the down draft might in oil or gas-fired heaters extinguish the flame and perhaps the associated pilot light. In this instance, the member 29 is a plate of generally V-shaped form having an apex 30 arranged to extend across the breeching section in opposition to the duct opening l2 and base margins arcuately shaped, as at 3| (Fig. 5), for close abutment with the breeching wall. The member is dimensioned to extend substantially across the breeching in the direction of the duct and its position and angularly disposed faces effectively cause the pressure resulting from the down drafts to swing the damper outwardly and be dissipated through the damper controlled opening.

Preferably the diverter is mounted for adjustment relative to the duct opening. Thus, the wall of the breeching opposite to the opening l2 has a longitudinally extending, inwardly opening channel member 32 fixed thereto as by rivets 33. The base margins 3| of the diverter are recessed, as at 34 (Fig. 2), to receive the channel member and a guide 35 slidably fitting the channel is secured to the diverter through narrowed ends 36. A set screw 31 mounted on the breeching for engagement with the guide maintains any position of adjustment. This arrangement permits the diverter to be adjusted properly with respect to the duct opening and the original manner of connection of the pipe section is immaterial. From the foregoing it will be evident that the present invention provides a single structure capable of adjustment to meet sub stantially any installation requirement. Thus, the need of a large number of styles for different conditions is avoided and the installation of equipmentis simplified and expedited.

I claim as my inventio'n:

1. A draft regulator having, in combination, a duct of square cross section for connection with a stack, a centrally open frame of complemental square shape adapted to be detachably mounted on said duct in any position in which the complemental squares register, an air flow control damper shaped to close the central opening in said frame, and a damper counterbalance including an arm connected with the damper to extend substantially normally of the pivotal axis thereof and across the plane of the damper, and a weight adjustable on said arm to positions on either side of said plane to balance the damper against the force of gravity in any position of the frame relative to the duct.

2. A draft regulator having, in combination, air passag means for connection with a stack including a substantially square frame defining an air inlet, an air flow control damper shaped to fit said inlet, detachable pivot means for swingably supporting said damper on said frame near any edge thereof, and a damper counterbalance including an arm connected with the damper to extend substantially normally of the pivotal axis thereof and across the plane of said damper, and a weight adjustable on said arm to positions on either side of said plane to balance the damper in any of its optional positions relative to the frame.

3. In a draft control device, the combination with a stack, of a draft duct connected therewith, a draft control damper for said duct pivotally mounted to swing outwardly in response to down draft pressure in the stack, and a diverter for down drafts mounted in said stack in opposition to said duct and comprising a, V- shaped member substantially traversing said stack with-the'apex thereof adjacent the opening of said duct into said stack.

4. In a draft control device, the combination of a stack, a draft duct communicating with said stack, automatically responsive draft control means pivotally mounted on said duct to swing outwardly in response to down draft pressure in the stack, a member dimensioned substantially to traverse the stack and angularly related thereto for directing sudden gas flow therein toward said duct, a longitudinally extending support on said stack, means on said member engaging said support and adjustable along the length thereof to dispose said member in operative relation to said duct, and means for securing said member in its adjusted position.

5. A draft regulator having, in combination, air passage means for connection with a stack including a frame defining an air inlet, an air flow control damper, detachable means for selectively positioning said damper for pivotal movement relative to said frame, and means adjustable to balance said damper in any selected position including a U-shaped support, means for securing said support to said damper through one leg of said support with the other leg of said support extending substantially transversely to and across the plane of said damper, and a weight member mounted on the last mentioned leg of said support for adjustment to positions on either side of said plane.

6. A draft regulator having, in combination, air passage means for connection with a stack including a frame defining an air inlet, an air flow control damper, detachable means for se lectively positioning said damper for pivotal movement in either direction from an air passage closing position about a horizontal axis located at the upper portion or the lower portion of said frame, and means adjustable to balance said damper in either of its said positions including a support fixed to said damper and extending across the plane of said damper in a direction substantially normal to said axis, and a weight adjustable on said support to positions on opposite sides of the plane of said damper.

7. A draft regulator having, in combination, air passage means for connection with a staclr including a frame defining an air inlet, an air flow control damper, detachable means for selectively positioning said damper for pivotal movement relative to said frame, and means adjustable to balance said damper in a selected position including an arm on said damper extending across the plane thereof substantially normally of the axis of said damper on the side of the pivot opposite to the center of mass of the damper, and a weight sliclably mounted on said arm and having an eccentrically located center of mass, said weight being adjustable to positions on both sides of the plane of the damper and being reversible on said arm to change the relative position of its center of mass.

8. A draft regulator having, in combination, air passage means for connection with a stack and having an air inlet, an air flow control damper shaped to fit said inlet, detachable means for pivotally mounting said damper near one edge thereof optionally near the upper or lower margins of said inlet, a damper counterbalance including an arm connected with the damper to extend substantially normally of the pivotal axis thereof across the plane of said damper, and a weight mounted on said arm for adjustment to positions on opposite sides of said plane and for reversal of the position of said weight on said arm on either side of said plane to dispose the center of itsrmass between said arm and axis when said damper is pivotally mounted at the upper margin of said inlet and to locate said center of mass on the side of said arm remote from said axis when said damper is pivotally mounted 

